摘要 |
In a wood-pellet cogeneration unit comprising a pellet feed, a combustion chamber, an ash removal device and a stirling engine, in order to achieve an optimum efficiency, provision is made for an exhaust gas recuperator (11) to preheat combustion air (10) and for wood pellets to be gasified with a portion of this hot air (13), for this portion (13) of the hot combustion air (10) to be directed above a grate (4) into a gasification combustion chamber (3 a) and for the fuel gas (18) thus produced to be sucked downwards through the grate (4) together with the ash by a side channel blower (7), for the fuel gas (18) under the grate (4) to be displaced with a flow impulse of the rest (14) of the hot combustion air (10) in such a way that, firstly, a low lambda value close to the CO limit is maintained and, depending on the temperature of the combustion chamber (3b), the combustion at a central nozzle (19) is stabilized, or, with increasing temperature of the combustion chamber (3b), the state of flameless combustion increasingly appears, wherein a potential vortex (20) is produced in the combustion chamber (3b), said potential vortex (20) intensively mixing exhaust gas (6), fuel gas (18) and hot combustion air (14), such that fuel gas (18) and ash particles burn completely. |